The development of cleansing products (including, without limitation, liquid hand soaps, body washes, shampoos, bath washes, hair conditioners, liquid dish detergents, car wash detergents, and the like) has long been driven by the challenge of providing a combination of performance properties such as good foaming, good cleansing, good rinsing, enhanced mildness, and improved skin feel. This combination of properties is even more challenging to provide in clear cleansing products, which are highly desired. Often the addition of a component to a cleansing composition formulation may enhance one property to the detriment of another desired property of the composition. For example, a composition may enhance skin conditioning by incorporating emollients at the expense of foaming. Therefore, those in the relevant art have been seeking new formulations to help achieve the balance of desirable performance properties.
Examples of developments in cleansing formulations seeking to balance low irritation, good tactile characteristics, good foaming, and good cleansing include U.S. Pat. No. 4,664,835 to Grollier et al., which describes a washing and cleansing formulation containing a synthetic surfactant and an anionic polymer; U.S. Pat. No. 5,646,100 to Haugk et al., which describes a liquid personal cleansing formulation containing an anionic surfactant, a betaine, and an alkyl polyglycoside; and U.S. Pat. No. 5,310,508 to Subramanyam et al., which describes a personal cleansing composition containing a salt of alcohol ethoxy glyceryl sulfonate (“AGS”) and a second synthetic surfactant.
It is well known that a liquid cleansing composition is typically aqueous and comprises one or more mild detersive surfactants and/or soaps. For example, conventional hand cleansers, body washes, shampoos, or liquid soap typically comprise a synthetic detersive and/or fatty acid soap and one or more foam stabilizing, wetting, or emulsifying surfactants.
However, cleansing compositions based on synthetic detergents often impart poor skin feel during and after use, and require additives to improve such tactile aspects of performance. One known emollient for improving skin feel and softness is polyethylene glycol-7 glyceryl cocoate (PEG-7 glyceryl cocoate), which is a polyethylene glycol ether of glyceryl cocoate containing an average of 7 moles of ethylene oxide. PEG-7 glyceryl cocoate is commercially available from a number of sources, such as Croda, Inc., under the trade name Glycerox HE, Cognis Corporation, under the trade name Cetiol HE, and Degussa Care Specialties, under the trade name Tegosoft GC. Although the incorporation of such an emollient may help to improve skin feel in cleansing compositions, it may not contribute to other necessary properties, such as attractive product appearance and viscosity, and may have a negative effect on foaming. Thus, additional components, such as foam builders and viscosity builders, may need to be incorporated into the cleansing compositions, which can lead to an increased cost in producing such compositions. Further, at concentrations higher than about 2% by weight, PEG-7 glyceryl cocoate may be difficult to mix into aqueous systems, especially at ambient temperatures, which may require more elaborate and/or costly mixing procedures to produce the cleansing compositions.
Despite these developments, there remains a need for a cleansing formulation that provides enhanced skin feel, low skin irritation, low skin drying, good cleansing ability, good foaming, and good rinsability characteristics/properties, especially in a clear cleansing product. There also remains a need for a cleansing formulation that utilizes components that are multi-functional, thereby obtaining a desired balance of properties with fewer components, which result in lower costs of production.